POSTALIAS(1) General Commands Manual POSTALIAS(1)
NAME
postalias - Postfix alias database maintenance
SYNOPSIS
postalias [-Nfinoprsuvw] [-c config_dir] [-d key] [-q key]
[file_type:]file_name ...
DESCRIPTION
The postalias(1) command creates or queries one or more Postfix alias
databases, or updates an existing one. The input and output file formats
are expected to be compatible with Sendmail version 8, and are expected
to be suitable for use as NIS alias maps.
If the result files do not exist they will be created with the same
group and other read permissions as their source file.
While a database update is in progress, signal delivery is postponed,
and an exclusive, advisory, lock is placed on the entire database, in
order to avoid surprises in spectator processes.
The format of Postfix alias input files is described in aliases(5).
By default the lookup key is mapped to lowercase to make the lookups
case insensitive; as of Postfix 2.3 this case folding happens only with
tables whose lookup keys are fixed-case strings such as btree:, dbm: or
hash:. With earlier versions, the lookup key is folded even with tables
where a lookup field can match both upper and lower case text, such as
regexp: and pcre:. This resulted in loss of information with $number
substitutions.
Options:
-c config_dir
Read the main.cf configuration file in the named directory in-
stead of the default configuration directory.
-d key Search the specified maps for key and remove one entry per map.
The exit status is zero when the requested information was found.
If a key value of - is specified, the program reads key values
from the standard input stream. The exit status is zero when at
least one of the requested keys was found.
-f Do not fold the lookup key to lower case while creating or query-
ing a table.
With Postfix version 2.3 and later, this option has no effect for
regular expression tables. There, case folding is controlled by
appending a flag to a pattern.
-i Incremental mode. Read entries from standard input and do not
truncate an existing database. By default, postalias(1) creates a
new database from the entries in file_name.
-N Include the terminating null character that terminates lookup
keys and values. By default, postalias(1) does whatever is the
default for the host operating system.
-n Don't include the terminating null character that terminates
lookup keys and values. By default, postalias(1) does whatever is
the default for the host operating system.
-o Do not release root privileges when processing a non-root input
file. By default, postalias(1) drops root privileges and runs as
the source file owner instead.
-p Do not inherit the file access permissions from the input file
when creating a new file. Instead, create a new file with de-
fault access permissions (mode 0644).
-q key Search the specified maps for key and write the first value found
to the standard output stream. The exit status is zero when the
requested information was found.
Note: this performs a single query with the key as specified, and
does not make iterative queries with substrings of the key as de-
scribed in the aliases(5) manual page.
If a key value of - is specified, the program reads key values
from the standard input stream and writes one line of key: value
output for each key that was found. The exit status is zero when
at least one of the requested keys was found.
-r When updating a table, do not complain about attempts to update
existing entries, and make those updates anyway.
-s Retrieve all database elements, and write one line of key: value
output for each element. The elements are printed in database or-
der, which is not necessarily the same as the original input or-
der. This feature is available in Postfix version 2.2 and later,
and is not available for all database types.
-u Disable UTF-8 support. UTF-8 support is enabled by default when
"smtputf8_enable = yes". It requires that keys and values are
valid UTF-8 strings.
-v Enable verbose logging for debugging purposes. Multiple -v op-
tions make the software increasingly verbose.
-w When updating a table, do not complain about attempts to update
existing entries, and ignore those attempts.
Arguments:
file_type
The database type. To find out what types are supported, use the
"postconf -m" command.
The postalias(1) command can query any supported file type, but
it can create only the following file types:
btree The output is a btree file, named file_name.db. This is
available on systems with support for db databases.
cdb The output is one file named file_name.cdb. This is
available on systems with support for cdb databases.
dbm The output consists of two files, named file_name.pag and
file_name.dir. This is available on systems with support
for dbm databases.
fail A table that reliably fails all requests. The lookup table
name is used for logging only. This table exists to sim-
plify Postfix error tests.
hash The output is a hashed file, named file_name.db. This is
available on systems with support for db databases.
lmdb The output is a btree-based file, named file_name.lmdb.
lmdb supports concurrent writes and reads from different
processes, unlike other supported file-based tables. This
is available on systems with support for lmdb databases.
sdbm The output consists of two files, named file_name.pag and
file_name.dir. This is available on systems with support
for sdbm databases.
When no file_type is specified, the software uses the database
type specified via the default_database_type configuration para-
meter. The default value for this parameter depends on the host
environment.
file_name
The name of the alias database source file when creating a data-
base.
DIAGNOSTICS
Problems are logged to the standard error stream and to syslogd(8) or
postlogd(8). No output means that no problems were detected. Duplicate
entries are skipped and are flagged with a warning.
postalias(1) terminates with zero exit status in case of success (in-
cluding successful "postalias -q" lookup) and terminates with non-zero
exit status in case of failure.
ENVIRONMENT
MAIL_CONFIG
Directory with Postfix configuration files.
MAIL_VERBOSE
Enable verbose logging for debugging purposes.
CONFIGURATION PARAMETERS
The following main.cf parameters are especially relevant to this pro-
gram.
The text below provides only a parameter summary. See postconf(5) for
more details including examples.
alias_database (see 'postconf -d' output)
The alias databases for local(8) delivery that are updated with
"newaliases" or with "sendmail -bi".
config_directory (see 'postconf -d' output)
The default location of the Postfix main.cf and master.cf config-
uration files.
berkeley_db_create_buffer_size (16777216)
The per-table I/O buffer size for programs that create Berkeley
DB hash or btree tables.
berkeley_db_read_buffer_size (131072)
The per-table I/O buffer size for programs that read Berkeley DB
hash or btree tables.
default_database_type (see 'postconf -d' output)
The default database type for use in newaliases(1), postalias(1)
and postmap(1) commands.
import_environment (see 'postconf -d' output)
The list of environment variables that a privileged Postfix
process will import from a non-Postfix parent process, or
name=value environment overrides.
smtputf8_enable (yes)
Enable preliminary SMTPUTF8 support for the protocols described
in RFC 6531, RFC 6532, and RFC 6533.
syslog_facility (mail)
The syslog facility of Postfix logging.
syslog_name (see 'postconf -d' output)
A prefix that is prepended to the process name in syslog records,
so that, for example, "smtpd" becomes "prefix/smtpd".
Available in Postfix 2.11 and later:
lmdb_map_size (16777216)
The initial OpenLDAP LMDB database size limit in bytes.
STANDARDS
RFC 822 (ARPA Internet Text Messages)
SEE ALSO
aliases(5), format of alias database input file.
local(8), Postfix local delivery agent.
postconf(1), supported database types
postconf(5), configuration parameters
postmap(1), create/update/query lookup tables
newaliases(1), Sendmail compatibility interface.
postlogd(8), Postfix logging
syslogd(8), system logging
README FILES
Use "postconf readme_directory" or "postconf html_directory" to locate
this information.
DATABASE_README, Postfix lookup table overview
LICENSE
The Secure Mailer license must be distributed with this software.
AUTHOR(S)
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
POSTALIAS(1)
Generated by dwww version 1.16 on Tue Dec 16 05:01:47 CET 2025.